Lewis Acid Mediated Alteration of Electron Density on a Copper Site via pπ-dπ Mixing Enhances the Electrochemical Nitrogen Reduction Reaction

Abstract

Strategic modulation of the electronic structure of the catalyst to foster the electrochemical nitrogen reduction reaction (eNRR) to the ammonia process significantly is still an area that needs to be explored. Herein, we report the incorporation of the Lewis acid into an electron-rich copper site regulating the electron density of the metal, which has been experimentally proved from the d-band center position to have a direct influence on the adsorption of N 2 compared to the protons. The catalyst boron doped copper-cuprous oxide hybrid system (B−Cu/Cu 2 O) has shown promising Faradaic efficiency of 32% at −0.2 V vs reversible hydrogen electrode (RHE) compared to the pristine cuprous oxide (Cu 2 O(N)) system. The in situ Fourier transform infrared study confirms the presence of intermediates evolved during the electroreduction process. This study demonstrates the design of the active center with a specific push−pull interaction via the pπ-dπ bonding−antibonding approach and can shed light on the electrochemical activation and reduction of dinitrogen to produce ammonia.